JP3353436B2 - Current amplification control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor amplifying device which does not feed back a current. When the motor is driven, the effect of the back electromotive force of the motor is corrected and the input current to the motor with respect to the motor current command value is corrected. The present invention relates to a current amplification control device having a method for eliminating an error.

[0002]

2. Description of the Related Art Conventionally, as a current amplification control device applied to a motor-driven four-wheel steering vehicle, for example, the one shown in FIG. 10 is known.

FIG. 10 shows a controller for controlling the positioning of the motor 1, a motor positioning control calculation unit 2 for calculating a current command value I ^{* based} on a motor angular position command value θ ^* and a motor angular position signal θ, and a motor positioning control unit. A current amplification control device 3 controls a motor input current according to a current command value I ^* from the control calculation unit 2. Then, the current amplification control device 3 detects the actual motor current I and feeds it back to obtain the motor current I that matches the current command value I ^* .

[0004]

However, in the above-described conventional current amplification control device, a triangular wave generator or a clockwise rotation circuit unit is used in the current detection unit 4 and the current feedback unit 5 for detecting the actually flowing motor current I. And the necessity of the left rotation circuit section, there is a problem that the cost of the controller is increased.

Accordingly, the applicant of the present application has previously filed Japanese Patent Application No. 6-38.
No. 71 (filed on Jan. 19, 1994), the power transistor switching time is calculated by an arithmetic unit for positioning the motor in consideration of the motor power supply voltage, the internal impedance of the motor, the delay of each element, and the like. A device has been proposed in which the power transistor is switched directly from the arithmetic unit based on the arithmetic result, and thereby a motor current that matches the current command value from the motor control unit can be obtained without feeding back the motor current.

However, in this prior art current amplification control device, since the influence of the motor back electromotive voltage is not taken into account, when the motor rotates at high speed, the current command value does not match the input current of the motor. Another problem is that the positioning response of the motor differs from the response desired by the designer.

The present invention has been made in view of such a problem. A first object of the present invention is to provide a current amplification control device for controlling a motor current based on a current command value. It is an object of the present invention to provide a device which obtains a positioning response of a motor which almost coincides with a design target when the motor rotates at a high speed, without requiring a feedback circuit and at a cost advantage.

A second object is to estimate the back electromotive voltage of the motor with high accuracy when the maximum current input to the motor is limited, in addition to the first object.

[0009]

According to a first aspect of the present invention, there is provided a current amplification control device for supplying a current to a motor a, as shown in FIG. Power transistor b to be supplied and motor a
A motor over angle position detection means c for detecting the angular position of the motor power supply voltage detecting means d for detecting the power supply voltage of the motor a, the nonlinearity and the modeling error of the dynamic characteristics of the motor a
A linear model in which the dynamic characteristics of the motor are always preset
A motor dynamic characteristic compensating unit e for calculating a motor input current for robust compensation control so that Le preset
Model matching to obtain the dynamic characteristics of the motor a
A motor positioning control unit f for calculating a motor input current by performing a motoring operation, and a motor dynamic characteristic compensating unit e.
Calculated motor input current and motor positioning
The motor input current calculated by the control unit f is added ,
A motor current command value determining unit g that determines a motor current command value, and a motor current command value determined by the motor positioning control unit f.
And motor input current and the motor over angle position detecting means c
Angular position of the motor detected by the
Motor operation of the linear model preset in the characteristic compensation unit e
The motor angular velocity is estimated based on the characteristics and
Motor angular velocity and pre-measured motor back-EMF voltage
A motor counter electromotive voltage estimation unit h which estimates a counter electromotive voltage of the motor a by multiplication of the number, the motor power supply voltage detecting hands
Motor back electromotive force estimated by the motor back electromotive voltage estimation unit h from the motor power supply voltage detected by the stage d
The value obtained by subtracting the pressure was divided by the impedance of the motor a and the power transistor b measured in advance .
Determined by the current value and the motor current command value determination unit g
The basic switching time calculating unit i which determines the basic switching time of the power transistor unit b in accordance with the ratio between the motor current command value, based on the motor current command value and the basic switching time, the power transistor And a power transistor / switching control unit j for controlling the switching of the unit b.

In order to achieve the second object, a current amplification control device according to a second aspect of the present invention, as shown in the claim correspondence diagram of FIG. When the maximum current input to the motor a is limited, the motor back electromotive voltage estimating unit h sets the current value u used for back electromotive voltage estimation as follows: when I ^* ≦ Imax, u = IM ^* I ^* > when Imax and ^{IM * ≦ Imax, u = IM} * - {IR * - (Imax -IM *)} / 2 I *> when Imax and IM ^*> Imax, u = Imax where, u; back EMF current I used in the estimate ^*; motor current command value Imax; motor input current maximum value IM ^*; motor positioning current IR ^*; characterized by using a motor dynamic characteristic compensation current.

[0011]

The operation of the first invention will be described.

When the current is supplied from the power transistor section b to the motor a, the motor dynamic characteristic compensating section e compensates for the non-linearity of the dynamic characteristic of the motor a and the modeling error, and modulates the motor.
The dynamic characteristics of the monitor always become a preset linear model.
The calculated motor input current for sea urchin robust compensation control, the motor positioning control section f, preset
Model match to obtain the dynamic characteristics of the motor a
The motor input current is calculated by performing the motor operation current compensation.
The motor input current calculated by the unit e and the motor input current calculated by the motor positioning control unit f are
The motor current command value is determined by the addition. Then, the motor counter electromotive voltage estimation unit h, the the motor input current calculated by the motor positioning control section f, of the motor detected by the <br/> motor over angle position detecting means c
Angular position and preset in the motor dynamic characteristic compensation unit e
Motor angle based on the linear model motor dynamics
Estimate the speed and measure the estimated motor angular speed in advance
The motor a is calculated by integrating with the back electromotive force constant of the motor
Is estimated. Then, in the basic switching time calculating section i, the motor power supply voltage detecting means d
The motor back electromotive voltage estimated by the motor back electromotive voltage estimation unit h is subtracted from the detected power supply voltage of the motor.
The value, the current value obtained by dividing the impedance of the pre-measured motor a and the power transistor unit b
And the motor determined by the motor current command value determination unit g.
Basic switching time of the power transistor unit b in accordance with the ratio of Ta current command value is determined, in the power transistor switching control unit j, based on the motor current command value and the basic switching time,
Switching of the power transistor section b is controlled.

Accordingly, the motor back electromotive voltage is estimated using the dynamic characteristics of the motor a, the positioning current, and the angular position information, while eliminating the need for a current detection unit and a current feedback circuit and making it advantageous in terms of cost. By correcting the motor power supply voltage directly detected using the electromotive voltage, a positioning response of the motor a substantially matching the design target can be obtained even when the motor a rotates at high speed.

The operation of the second invention will be described.

When the maximum current input to the motor a is limited, the motor back electromotive voltage estimating section h converts the current value u used for estimating the back electromotive voltage into the motor input value for the current command value I ^* as described above. According to the magnitude relation between the maximum current value Imax and the maximum motor input current value Imax with respect to the motor positioning current IM ^* , the weights of the motor dynamic characteristic compensating unit e and the motor positioning control unit f are defined to be the same from IM ^* to Imax. This makes it possible to more accurately estimate the angular velocity of the motor a, and as a result, it is possible to accurately estimate the back electromotive voltage of the motor a when the maximum current input to the motor a is limited.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described.

FIG. 2 is a block diagram showing a current amplification control device according to an embodiment of the present invention.

As shown in FIG. 2, the apparatus of the embodiment includes a motor 100 (corresponding to a motor a), a controller 101,
It comprises an angular position detecting device 102 (corresponding to a motor angular position detecting means c).

The controller 101 inputs a motor angular position signal θ from the motor angular position detecting device 102, a motor power supply voltage VE, and a motor angular position command value θ ^* ,
Arithmetic unit 111 for outputting power transistor control signal
And the motor 1 based on the power transistor control signal.
A power transistor unit 110 (corresponding to a power transistor unit b) for supplying a current to the power supply unit 00 is provided.

The arithmetic unit 111 has a motor positioning control unit 130 and a current amplification control arithmetic unit 131.

A description will be given of a case where the motor positioning controller 130 is configured by combining the rear wheel steering control system and the current amplification controller of the present embodiment to form a motor positioning controller (see FIG. 3).

The motor positioning control unit 130 compensates for non-linearity or model error of the control object by robust compensation, and controls the control object to always be a linear model determined by the designer. And a model matching control unit 130b for controlling the response of the control target so that the response desired by the designer is obtained.
(Equivalent to the motor positioning control unit f) and the output IR ^* of the robust compensator 130a and the model matching control unit 130 in consideration of the capabilities of elements such as the power transistor unit 110.
motor input current limiter 13 for calculating the current command value I ^* by limiting the maximum value of the sum of the outputs IM ^* of b.
0c (corresponding to the motor command current value determination unit g),
A motor current command value I ^* , a motor dynamic characteristic compensation current IR ^* , a motor positioning current IM ^* , and a motor angular position θ are output to the current amplification control calculation unit 131.

As shown in FIG. 2, the current amplification control operation unit 131 includes a motor power supply voltage detection unit 120 (corresponding to motor power supply voltage detection means d) and a basic DUTY ratio calculation unit 1
21 (corresponding to the basic switching time calculation unit i) and DU
It has a TY ratio correction amount calculator 122, a power transistor / switching controller 123 (corresponding to a power transistor / switching controller j), and a motor back electromotive voltage estimator (corresponding to a motor back electromotive voltage estimator h) 124. It is configured.

The motor power supply voltage detector 120 detects the power supply voltage VE of the motor 100. The basic DU
The TY ratio calculation unit 121 is provided with the motor 10 measured in advance.
The switching ON ratio (PWM-DUTY ratio) in the power transistor switching cycle FW is calculated from the internal resistance of the power transistor unit 110 and the combined resistance value such as the ON resistance of the power transistor unit 110 and the motor power supply voltage VE. Output stage switching time T _D
Is calculated. The DUTY ratio correction amount calculating unit 122 calculates the correction amount of basic output stage switching time T _D which is calculated by the basic DUTY ratio calculating unit 121 calculates a correction output stage switching time T _C. The power transistor
The switching control unit 123, based on the basic output stage switching time T _D and the correction output stage switching time T _C was added combined time T _ON and the motor current command value I ^*, any one of the power transistor for controlling the switching of the power transistor 110 Outputs control signal.

The motor back electromotive voltage estimating unit 124 receives the motor current command value I ^* , the motor positioning current IM ^* , and the motor angular position θ, and obtains a diagram from the transfer characteristic of the control object linearized by the robust compensator 130a. A motor angular velocity estimator as shown in FIG. 4 is constructed, and a motor angular velocity estimated value dθ ^# obtained from the motor angular velocity estimator and a back electromotive force constant KR which is a specification value of the motor 100 measured in advance.
As a result, the back electromotive voltage VR generated by the rotation of the motor 100 is estimated and detected.

The superscript used in this embodiment is:
* Indicates a target value, and # indicates an estimated value.

Next, the operation will be described.

[Current Amplification Control Operation Process] FIG. 5 is a flowchart showing the current amplification control operation process performed by the arithmetic unit 111 of the controller 101. Each step will be described below.

In step 50, it is determined whether it is the positioning time of the motor 100 or not.

In step 51, the motor angular position signal θ
And the motor angular position command value θ ^* are input.

In step 52, the robust compensator 130
At a, the motor dynamic characteristic compensation current IR ^* is calculated.

In step 53, a motor positioning current IM ^* is calculated in the model matching control section 130b.

In step 54, the motor current command value I ^* is determined by adding the motor dynamic characteristic compensation current IR ^* and the motor positioning current IM ^* .

In step 55, it is determined whether or not it is the operation time of the power transistor control signal.

In step 56, the motor power supply voltage VE
Is entered.

In step 57, the motor back electromotive voltage estimator 124 calculates the back electromotive voltage VR from the motor angular position signal θ, the motor dynamic characteristic compensation current IR ^*, and the motor positioning current IM ^* .

In step 58, the motor power supply voltage VE
And the combined resistance value R _M of the ON resistance of the internal resistor and a power transistor 110 of the motor 100 is previously measured counter electromotive voltage VR and the motor current command value I ^*, any one of the switching ON of the power transistor switching period F _W (PWM-DUTY ratio) D _T is calculated.

In step 59, the PWM-DUTY ratio D
_T and the power transistor switching period F _W by the power transistor ON reference time is a basic output stage switching time T _D is calculated, the gate resistor R ₁ and the gate capacitance C in the power transistors ON reference time T _D and the power transistor unit 110 switching extended time T _C of the gate is a corrected output stage switching time of the power transistor unit 110 is calculated by _1.

In step 60, the power transistor switching time T _ON (= T _D + T) is determined by the gate switching extension time T _C and the power transistor ON reference time T _D.
C ) is calculated.

In step 61, the motor current command value I
^The output direction (forward or reverse) is determined from ^* , and a power transistor switching control signal is output according to the power transistor switch time T _ON .

[Current Amplification Control Operation] The current amplification control is performed according to the flowchart shown in FIG.

That is, at step 57, the back electromotive voltage VR is calculated by the motor back electromotive voltage estimating section 124. The estimation of the motor back electromotive voltage VR will be described.

First, a motor angular velocity estimator as shown in FIG. 4 is constructed from the transfer characteristic of the control object linearized by the robust compensator 130a. The transfer characteristic of the linearized control object is expressed by the following equation. Can be represented by

Θ = n _mo / (s ² + d _m1 s + d _mo ) (1) where s is a differential operator. The state equation of the motor angular velocity estimator can be expressed by the following equation.

[0046] ^{dω / dt = A # · ω} + Kθ + B # · u ... (2) dθ # = Dω + Hθ ... (3) However, u; motor angular velocity estimator input ^{(= IM *) A # =} -d m1 -L B # _{= Ln mo K = -L (d} m1 + L) -d mo H = L dθ #; and the motor angular velocity estimate designer is calculated from the constants above formula arbitrarily set d [theta] ^#,; motor angular velocity estimate L
The back electromotive force VR generated by the rotation of the motor 100 is estimated and calculated by the following equation based on the back electromotive voltage constant KR which is a specification value of the motor 100 measured in advance.

VR = KR · dθ ^# (4) Then, at step 58, the power transistor
The PWM-DUTY ratio _DT , which is the ratio of switching ON in the switching period _FW , is a term (VE−V) obtained by correcting the detected motor power supply voltage VE with the back electromotive force VR.
It can be obtained by the following equation using VR).

[0048] I _MAX = however _{(VE -VR) / R M ...} (5), I MAX; current value when PWM-DUTY ratio ^{_{100% D T = I * /}} I MAX ... (6) However, like this Only the current amplification control method of controlling the motor current I by switching the power transistor unit 110 requires the power transistor unit 1
Due to the response delay of the gate voltage V _C due to the gate resistance R ₁ (including the wiring resistance) and the gate capacitance C ₁ and the switching delay of the gate, the motor applied voltage has a delay on the current application start side. It becomes a waveform, and the motor current command value I ^* does not match the motor current.

Therefore, the gate switching time may be extended so as to have an area equal to the area of the motor applied voltage _VME missing from the power transistor switching reference signal due to the delay.

Firstly, the area S _G of lost portion of the motor applied voltage V _ME is calculated by the following equation.

[0051] _{S G = V ME * T D} -∫ {1-exp (-t / T G) V ME} dt + V ME * L G = V ME * T D - [t + exp (-t / T G) / T ^{_{G] 0 TD * V ME +}} V ME * L G = (V ME / T G) {1-exp (-T D / T G)} + V ME * L G ... (7) however, T _G = R ₁ * C _1; gate resistor, the time constant due to the gate capacitance _{T D = D T / F W} ; power transistor ON reference time L _G; gate switching delay time therefore, switching extension time T _C of the gates to the following equation (8) Become.

T _C = (1 / T _G ) {1−exp (−t / T _G )} + L _G (8) Here, the values of L _G , R ₁ , and C ₁ are based on the specifications and experiments of the device. Beforehand. Further, the switching extension time T _C may be obtained from a map having the power transistor ON reference time T _D as a function.

In step 60, the power transistor switch time T _ON is calculated by the following equation from the power transistor ON reference time T _D , the gate switching extension time T _C , and the power transistor ON reference time T _D. .

T _ON = T _D + T _C (9) In step 61, the output direction (forward or reverse) is determined from the motor current command value I ^* , and the power is switched according to the power transistor switch time T _ON . A transistor switching control signal is output.

By performing the above-described arithmetic processing, the motor current command value I ^* and the motor current I can be matched even during a positioning response in which the motor 100 rotates at high speed without feeding back the motor current. Current amplification control with high response and high response can be achieved.

[Another Example of Back EMF Estimation] In the above back EMF estimation method, the input u of the motor angular velocity estimator of the motor back EMF estimation unit 124 has a desired response to the linearized control object. The motor positioning current I, which is the output of the model matching control unit 130b, which is the input for obtaining
M ^* is used.

However, if the maximum value of the motor current command value I ^{* obtained} by adding the motor positioning current IM ^* and the motor dynamic characteristic compensation current IR ^* is limited, the motor 10
Since the contribution of the motor positioning current IM ^* input to 0 is not clear, the following conditions are applied to determine the motor angular velocity estimator input u. By adding this condition, the angular velocity of the motor 100 can be more accurately estimated.

When I ^* ≦ Imax, when u = IM ^* I ^* > Imax and when IM ^* ≦ Imax, the weights of the robust compensator 130a and the model matching control unit 130b in this positioning control system are the same. ^{= IM * - {IR * -} (Imax -IM *)} when / 2 I ^*> Imax and IM ^*> Imax, u = Imax where, Imax is the limit value of the motor input current limiting unit 130c.

[Simulation Result] FIG. 6 shows a step response characteristic in the prior art in which the back electromotive voltage of the motor is not taken into consideration. The motor power supply voltage is not corrected by the back electromotive voltage of the motor. Since the motor angular position characteristic is given by a constant voltage, the actual characteristic has a large deviation from the target characteristic.

FIG. 7 shows a step response characteristic when the first embodiment of the present invention is applied. The DU is obtained by correcting the motor power supply voltage by the estimated back electromotive voltage of the motor.
The value used for calculating the TY ratio was close to the actual value, and in the motor angular position characteristics, the actual characteristics were highly consistent with the target characteristics, confirming the effectiveness of the first invention.

FIG. 8 is a graph showing characteristics of comparison of the voltage applied to the motor when the first invention is applied. FIG. 9 is a graph showing the characteristics of the motor applied when the above condition is added to the input u of the motor angular velocity estimator according to the second invention. It is a voltage comparison characteristic figure.

From the comparison of the simulation results, it has been confirmed that by adding the above condition to the input u of the motor angular velocity estimator, the back electromotive force of the motor can be estimated more accurately than when no condition is added. Was done.

Next, the effects will be described.

(1) In the current amplification control device according to the embodiment, the back electromotive force VR of the motor 100 is determined by the dynamic characteristics of the motor 100, the positioning current IM ^* of the motor 100, and the angular position signal θ of the motor 100. And a device for controlling the switching of the power transistor unit 110 by correcting the motor power supply voltage VE directly detected by using the estimated back electromotive voltage VR, so that the current detection unit and the current feedback circuit are not required, and the cost is reduced. Advantageously, it is possible to provide an apparatus that obtains a positioning response of the motor 100 that substantially matches a design target when the motor 100 rotates at a high speed.

(2) In the current amplification control device of the embodiment, when estimating the back electromotive voltage VR, the motor current command value I ^{* obtained} by adding the motor positioning current IM ^* and the motor dynamic characteristic compensation current IR ^{* .} When the maximum value of the motor angular velocity estimator is limited, a condition for determining the input u of the motor angular velocity estimator is added. Therefore, the contribution of the motor positioning current IM ^* input to the motor 100 becomes clear, and the motor It is possible to estimate the angular velocity of 100, and as a result, the estimation accuracy of the motor back electromotive voltage VR can be improved.

(3) In the current amplification control device of the embodiment, the power transistor ON reference time T _D which is the basic output stage switching time and the gate switching extension time T _C which is the corrected output stage switching time are added. time T _oN and, on the basis of the motor current command value I ^*, due to a device for controlling the switching of the power transistor 110, regardless of the variation in the dynamic characteristics of the power transistor unit 110, the motor current command value I ^* On the other hand, it is possible to obtain a highly consistent motor current I.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to the embodiment, and any changes or additions without departing from the spirit of the invention are included in the invention. It is.

For example, in the embodiment, an example in which the present invention is applied to a motor drive current control unit of a 4WS system has been described. However, the present invention is applied to drive current control units of various systems that control a motor drive current other than the 4WS system. be able to.

[0069]

According to the first aspect of the present invention,
In a current amplification controller that controls the motor current based on the current command value, the basic switching time to calculate the basic output stage switching time of the power transistor unit from the motor power supply voltage and the measured internal resistance of the motor and the impedance characteristics of the power transistor unit Since the device includes an arithmetic unit and a power transistor switching control unit that controls switching of the power transistor unit based on a current command value supplied to the power transistor unit and a basic output stage switching time, current detection is performed. An advantage is obtained in that a device that obtains a positioning response of the motor that substantially matches the design target when the motor rotates at a high speed can be provided while requiring no parts or a current feedback circuit and making it advantageous in cost.

According to a second aspect of the present invention, in the current amplification control device for controlling the motor current based on the current command value, the basic switching time calculation unit takes into account the dynamic characteristics of the power transistor unit. A switching time correction amount calculating means for calculating a correction amount of the calculated basic output stage switching time, wherein the power transistor / switching control unit includes a basic output stage switching time and a correction output stage calculated by the switching time correction amount calculating means. Since the switching of the power transistor section is controlled based on the current command value and the time obtained by adding the switching time, in addition to the above-described effects, when the maximum current input to the motor is limited, the reverse of the motor is accurately performed. The effect that the electromotive voltage can be estimated is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing a current amplification control device of the present invention.

FIG. 2 is a block diagram showing a current amplification control device according to an embodiment of the present invention.

FIG. 3 is a detailed block diagram of a motor positioning control unit of the embodiment device.

FIG. 4 is a control block diagram of a motor angular velocity estimator of a motor back electromotive voltage estimating unit of the example apparatus.

FIG. 5 is a flowchart showing a flow of a current amplification control processing operation performed by the arithmetic unit of the controller according to the embodiment of the present invention.

FIG. 6 is a simulation characteristic diagram of a step response according to the prior art in which motor back electromotive force estimation is not performed.

FIG. 7 is a simulation characteristic diagram of a step response according to the embodiment technology based on motor back electromotive voltage estimation.

FIG. 8 is a characteristic diagram of a motor applied voltage simulation by estimating a motor back electromotive voltage in the first invention.

FIG. 9 is a characteristic diagram of a motor applied voltage simulation by estimating a motor back electromotive voltage in the second invention.

FIG. 10 is a block diagram showing a conventional current amplification control device.

[Explanation of symbols]

 a motor b power transistor section c motor angular position detecting means d motor power supply voltage detecting means e motor dynamic characteristic compensating section f motor positioning control section g motor current command value determining section h motor back electromotive voltage estimating section i basic switching time calculating section j Power transistor switching controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI G05D 3/12 G05D 3/12 T 305 305L 305V H02P 5/06 H02P 5/06 X (JP, A) JP-A-58-99278 (JP, A) JP-A-57-199487 (JP, A) JP-A-57-199486 (JP, A) JP-A-5-22978 (JP, A) ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) H02P 5/00-5/26 H02P 7/00-7/34 G05B 13/02 G05D 3/00 G05D 3/12

Claims (2)

(57) [Claims] And 1. A motor for supplying a current to the power transistor section, a motor over angle position detecting means for detecting the angular position of the motor, the motor power supply voltage detecting means for detecting a power supply voltage of the motor, the dynamic characteristics of the motor Compensate for nonlinearities and modeling errors
The dynamic characteristic of the motor is always a preset linear model
And a motor dynamics compensator to calculate the motor input current for robust compensation control and a model to obtain the preset motor dynamics
A motor positioning control unit that calculates a motor input current by performing a matching operation; and a motor input control unit that is calculated by the motor dynamic characteristic compensation unit.
Force current and calculated by the motor positioning controller
A motor current command value determining unit that adds a motor input current to determine a motor current command value; and a motor calculated by the motor positioning control unit.
An input current, is detected by the motor over angle position detecting means
Motor angular position and the motor dynamic characteristics compensation section
Based on the motor dynamic characteristics of the preset linear model,
Motor angular velocity, and the estimated motor angular velocity
And the countermeasure voltage constant of the motor
A motor counter electromotive voltage estimation unit that estimates a counter electromotive voltage of the motor Ri, motor detected by the motor power supply voltage detecting means
Estimated by the motor back electromotive voltage estimation unit from the power supply voltage of
The current value obtained by dividing the value obtained by subtracting the back electromotive voltage of the motor by the impedance of the motor and the power transistor portion measured in advance, and the motor current command value
According to the ratio with the motor current command value determined by the determination unit
The basic switching time calculation unit which determines a basic switching time of the power transistor unit Te, the motor current command value and based on the basic switching time, the power transistor switching control unit for controlling the switching of said power transistor unit A current amplification control device, comprising: 2. The current amplification control device according to claim 1, wherein when the maximum current input to the motor is limited, the motor back electromotive voltage estimating unit sets a current value u used for back electromotive voltage estimation as: when I ^* ≦ Imax, when u = IM ^* I ^*> Imax and ^{IM * ≦ Imax, u = IM} * - {IR * - (Imax -IM *)} / 2 I *> Imax and IM ^*> Imax When u = Imax, u: Current value used for estimating the back electromotive voltage I ^* ; Motor current command value Imax; Motor input current maximum value IM ^* : Motor positioning current IR ^* ; Motor dynamic characteristic compensation current A current amplification control device characterized by the above-mentioned.